Geomessaging, also referred to as geocasting, has been developed to enable the distribution of messages to a designated geographic area. In cases in which a network service includes a localized information service, a so-called geomessaging function can be introduced into the mobile communication network. On one side, this geomessaging function maintains some relationship to all mobile terminals (clients) and their geographical location. On the other side, it exposes an interface to a multitude of services (network internal and external), which allows sending messages into a spatial area without knowing individual client's locations. For this purpose, a geomessaging server component tracks the position of its client using an optimized, grid-based scheme. The geographical area that is covered by the cellular communications network is mapped by a grid with grid lines and grid fields. The grid may comprise several grid spacings. Clients notify the geomessaging server when they move to another area of the grid. Based on this mapping of clients to grid areas stored on the geomessaging server, the geomessaging server can serve distribution requests by different application servers and forward messages in nearly real-time to clients in a geographic area as specified by the application server. A high level architecture is schematically illustrated by FIG. 1, wherein AS1 and AS2 are two application servers and GM is a geomessaging server.
G. Jodlauk, R. Rembarz, Z. Xu, “An Optimized Grid-Based Geocasting Method for Cellular Mobile Networks,” Proc. 18th ITS World Congress, Orlando, Fla., USA, Oct. 16-20, 2011, pp. 1463ff, relates to a geocast scheme based on a grid-based localization. In this approach, a grid is defined as an area covering the entire served geocast region. The grid subdivides the served geocast area into tiles. Clients only report their location to the geocast server when they move from one tile to another. As long as a client remains in its tile, it stays silent. The individual clients only have the knowledge of the tile they are currently in. The client-side geocast application used the positioning system (e.g. GPS) to regularly check whether it moves out of the current tile. When it crosses the border of the tile, it contacts the server and uploads new geographic coordinates. In response to this update, the server updates its per-tile client list and sends the boundaries of the new tile back to the client. The client can then stay silent again until it reaches the boundaries of the new tile, and the procedure starts over.
International application WO 2012/055433 A1 relates to similar methods and systems for providing a network service in a cellular communication network.
It is desirable to improve the methods and architectures of the prior art, notably as far as providing efficient implementation solutions is concerned.